Openly gay Conservative MP and shadow leader of the House of Commons Alan Duncan has been caught on camera saying that MPs are now “treated like s**t” and are forced to live on “rations” since the expenses scandal broke.

He was filmed by campaigner Heydon Prowse, the editor of Don’t Panic magazine. He was invited by Duncan to visit parliament in June.

Duncan, a multi-millionaire who receives an MPs’ salary of around £65,000, was forced to apologise and pay back nearly £4,000 he claimed for gardening costs.

Referring to parliament, he said: “No one who has done anything in the outside world, or is capable of doing such a thing, will ever come into this place ever again, the way we are going.”

“I spend my money on my garden and claim a tiny fraction based on what is proper. And I could claim the whole bloody lot, but I don’t.”

When asked how much he spends on his garden, he said: “About £2,000 a year and this was £1,000 a year on expenses, you know. It’s just, I’m afraid the world has gone mad.”

He summarised life as an MP as: “Basically, it’s being nationalised, you have to live on rations and are treated like s**t.”

Duncan told the London Evening Standard his “rations” comment had been intended as a joke.

He added: “I’m sorry that I was so generous in inviting this person to the Commons for a drink.”